PARMELIA | PARMELIACEE 125 
is dorsiventral, with the gonidial layer almost touching each margin, 
and rising in pyramid-like projections towards the upper cortex. The 
apothecia, which are frequent, are subterminal. Spermogones are 
numerous and prominent, with spermatia 5 » long and 1 p thick. 
Lightfoot’s description leaves no doubt as to the identity of Lichen 
corniculatus, which antedates both Hudson’s and Weber’s names. 
Hab. On rocks and boulders in mountainous districts.—Distr. 
Rather rare in W. and N. England and N. Wales; more frequent in 
the Scottish Highlands; rare in S.W. Ireland.—B. M. Dartmoor, 
Devon; Malvern Hills, Worcestershire ; Sugar Loaf Mt., Monmouth- 
shire; Cader Idris, Merioneth; The Glyders, Snowdon and Moel 
Siabod, Carnarvonshire; Llangollen; Denbighshire; Crickley Scar, 
Yorkshire; Egglestone, Durham; The Cheviots, Northumberland ; 
Mardale, Westmoreland; Ennerdale, Cumberland; New Galloway, 
Kirkeudbrightshire; Ben More, Ben lLawers, Ben Vrackie and 
Aberfeldy, Perthshire; Clova Mts., Head of the White Water and 
Katelaw, Forfarshire; near Invercauld, Craig Coinnoch, Morrone, 
Glen Callater, Glen Dee and Ben-naboord, Braemar and Hill of Ardo, 
Aberdeenshire; Ben Nevis, Invernessshire; Applecross, Rossshire ; 
Dunkerron, Kerry. 
8. P. stygia Ach. Meth. Lich. p. 203 (1803).—Thallus 
orbicular, appressed, somewhat shining, smooth, olive-brown or 
blackish, the lobes narrow, with spreading palmate branching, 
somewhat convex and incurved at the apices, beneath pitch- 
black but paler towards the edge, with few stoutish rhizine 
(K—, CaCl—). Apothecia becoming large and flexuose, dark 
olive-brown or black, with a dark-coloured crenulate margin ; 
spores small, 8-10 » long, 6-7 p» thick.—S. F. Gray Nat. Arr. i. 
p. 441 ; Hook. Fl. Scot. i. p. 54 & in Sm. Engl. Fl. v. p. 202 ; 
Mudd Man. p. 100; Cromb. Lich. Brit. p. 35; Leight. Lich. FI. 
p. 124; ed. 3, p. 116. Lichen stygius L. Sp. Pl. p. 1143 (1753) ; 
Dicks. Pl. Crypt. fase. iii. p. 16; With. Arr. ed. 3, iv. p. 30; 
Engl. Bot. t. 2048. 
Ezxsicc. Dicks. Hort. Sicc. fase. ii. n. 25 pro parte. 
_ Might be confused with Platysma fahlunense on account of the 
partly shining thallus, but it is blacker, and the lobes thicker and 
more convex. It is generally fertile. Spermogones are frequent, 
with spores 5 » long, 1 p» thick. 
Hab. On granitic and quartzose rocks and boulders in subalpine 
and alpine regions.—Distr. Local and rare among the Grampians, 
Scotland..—b. M. Ben More, Perthshire ; Lochnagar, Ben-naboord and 
Ben Macdhui, Braemar, Aberdeenshire ; Ben Nevis, Invernessshire. 
B. Rhizine abundant or scanty, but absent from the margin 
(Amphigymnia). 
a. Thallus glaucous-grey. 
9. P. perlata Ach. Meth. Lich. p. 216 (1803).—Thallus 
horizontal, wide-spreading, somewhat orbicular in outline, smooth, 
glaucous greyish-white, lobate, the lobes rounded, ascending, 
